DESCRIPTION: Glycans are polymeric carbohydrates found in all living things. They are of fundamental importance within the body because of their involvement in cell-cell communication and other cellular recognition processes and they are of fundamental importance in infectious disease because of their presence as antigenic determinants in bacteria, fungi, and viruses. Determining the structures of these molecules at a molecular level and establishing the structural motifs important in these molecular recognition processes is one of the central themes in the field of glycobiology but, unfortunately, progress toward these goals has been hampered by the lack of a truly general method for structural analysis using small amounts of material. One of the major goals of the present proposal is to develop electrochemical reductive cleavage as a means to fully characterize glycans. Guiding the development of the method will be its application to the analysis of synthetically prepared oligosaccharide libraries, glycoprotein- and glycolipid-derived oligosaccharides, and the capsular polysaccharides and lipopolysaccharides derived from several strains of Porphyromonas gingivalis, one of the major causative agents of periodontal disease. The other major goal of the present proposal is to develop a variant of the Reductive-Cleavage Method that is at least 1000-fold more sensitive. The proposed method will take advantage of the sensitivity of an electron capture GLC detector by analyzing reductive cleavage fragments as their trifluoropropyl ether/trifluoropropionyl ester derivatives. Guiding the development of this method will also be its application to glycoprotein- and glycolipid-derived oligosaccharides.